United States launched fresh strikes Thursday on Iran with bridges and transport infrastructure among the apparent targets, as Tehran responded with attacks on US allies in the Gulf. NDTV reported.

The rekindled fighting over the vital Strait of Hormuz came a month after the signing of a preliminary deal that aimed to end the conflict, which broke out in late February with massive US-Israeli strikes on Iran.

US Central Command (CENTCOM) announced it was conducting a new wave of strikes on Thursday evening to "further degrade Iranian military capabilities" the sixth straight night of attacks by American forces.

Iranian state media reported strikes on two bridges, a railway station and an airport in the southern part of the Islamic republic, near the strategic strait, which is crucial to global oil and gas flows.

Three people were killed in the attack on the bridges in Hormozgan province, state TV said on Telegram.

State TV in Tehran earlier reported two explosions in the western city of Bushehr -home to Iran's only civilian nuclear plant  in a "continuation of the American enemy aggression".

Tehran had earlier warned it would target infrastructure across the region if US President Donald Trump followed through on a threat to attack power plants and bridges in Iran -- though the White House said he remained "open to diplomacy".